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CF-Justice Center-SY 950515 Geotechnical Exploration PROPOSED POLICE STATION -- Parkway Boulevard Coppell, Texas ATEC Report No. 25-02-95-00092 -- City of Coppell 500 Southwestern Boulevard Coppell, Texas 75019 Attention: Mr. Clay Phillips May 15, 1995 ATEC Associates, Inc. ~Wl 11356 Mathis Avenue Dallas, Texas 75229-3157 (214) 556-2204, FAX (214) 556-1753 May 15, 1995 -- City of Coppell 500 Southwestern Boulevard Coppell, Texas 75019 Attention: Mr. Clay Phillips -- Subject: Geotechnical Exploration PROPOSED POLICE STATION Parkway Boulevard Coppell, Texas ATEC Report No. 25-02-95--00092 Dear Mr. Phillips: ATEC Associates, Inc. (ATEC) has completed the geotechnical exploration at the above referenced project site. This study was completed in accordance with ATEC Proposal No. 25- 02-95-00218 dated February 27, 1995 and authorized by your Purchase Order Number 012378 _ dated March 9, 1995. This report contains the results of our findings, an engineering interpretation of these with _ respect to the available project characteristics and recommendations to aid design and construction of foundations and other earth connected phases of this project. We wish to remind you that all soil and rock samples obtained during the field investigation will. be retained for a - period of 30 days and then discarded unless you request otherwise. We appreciate the opportunity to be of service on this project. After you have had an opportunity to review this report, we will contact you to answer any questions you may have. In the meantime, if we can be of further assistance, please call us at (214) 556-2204. -- Sincerely, C. Randal French, E.I.T. -- Project Engineer I Manager, GME Div'~~,'_':' ~,[~O~ cc: (2) Client -- (3) Phillips Swager Associates - G. Schon CRF/DPZ:crf American Testing and Engineering Corporation Consulting Environmental, Geotechnical and Offices in Major U.S. Cities/Since 1958 Materials Engineers TABLE OF CONTENTS 1.0 INTRODUCTION ........................................ 1 2.0 PROJECT CHARACTERISTICS ............................... 1 3.0 GENERAL SUBSURFACE CONDITIONS ......................... 2 3.1 General Area Geology ................................ 3 3.2 Soil Profile ...................................... 3 3.3 Groundwater Conditions .............................. 4 4.0 DESIGN RECOMMENDATIONS .............................. 5 4.1 General Considerations ............................... 5 4.2 Drilled Straight Shaft and Grade Beam Foundation System .......... 7 4.2.1 General Design Considerations ...................... 7 4.2.2 Uplift Considerations ............................ 9 4.3 Suspended Floor Slab System ........................... 10 4.4 Floor Slab on Improved Subgrade ......................... 10 4.5 Pavement Subgrade Preparation and Pavement Design ............ 12 4.6 Drainage ........................................ 15 5.0 GENERAL CONSTRUCTION PROCEDURES AND RECOMMENDATIONS . . . 16 5.1 Site Preparation and Grading ............................ 17 5.2 Drilled Shaft Excavations .............................. 17 5.3 Fill Placement and Compaction .......................... 18 5.4 Groundwater ..................................... 19 6.0 QUALIFICATIONS OF RECOMMENDATIONS ..................... 19 IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL REPORT APPENDIX Figure 1 - Boring Location Plan Field Investigation Procedures Laboratory Investigation Procedures Table 1 - Free Swell Test Results Table 2 - Unconfined Compressive Strength Test Results on Gray Shale Specimens Record of Soil Exploration Sheets (Boring Logs) Key to Soil Symbols and Classification Geotechnical Exploration PROPOSED POLICE STATION Parkway Boulevard Coppell, Texas ATEC Report No. 25-02-95-00092 1.0 INTRODUCTION ATEC Associates, Inc. (ATEC) was retained by the City of Coppell, Texas to perform a geotechnical exploration for the proposed police station facility to be constructed south of Parkway Boulevard, just east of its intersection with Denton Tap Road in Coppell, Texas. The site and our understanding of the proposed construction are described in more detail in Section 2.0. The purpose of this geotechnical exploration was to determine the general subsurface conditions at the proposed construction site by drilling test borings and evaluating these with respect to the foundation concept and design. The subsurface conditions found in the eight test borings drilled for this project are summarized in Section 3.0. The design recommendations for the foundation, floor slab, and pavement systems are presented in Section 4.0. Also included is an evaluation of the site with respect to potential construction problems and recommendations dealing with the earthwork quality control testing during construction. The recommendations pertaining to construction are included in Section 5.0. Qualifications of our recommendations are discussed in Section 6.0. Text figures, field and laboratory investigation procedures and test results are included in the Appendix along with the boring logs. 2.0 PROJECT CHARACTERISTICS The subject site for the proposed police station is located on the south side of Parkway Boulevard, just east of its intersection with Denton Tap Road in Coppell, Texas. The property is bound on the south and west by unimproved pasture land'. The City of Coppell City Hall is - 1 northeast of the subject site. Residential properties are located to the east. The subject site has frontage and access to Parkway Boulevard on its northern boundary. The property for the proposed new facility consists of vacant undeveloped pasture land. The site is covered with various short to medium height grasses and weeds. The southern portion of the site is enclosed by a barbed-wire fence. The northern edge of this fence line dissects the proposed building location. Small areas of ponded water were located northeast and north of the proposed building location. The topography of the site is relatively flat with a slight slope to the north-northeast. The elevation change across the site is on the order of 2 to 4 feet. It is our understanding the proposed police station will consist of a single-story structure with a footprint of approximately 20,000 square feet. The proposed building will be a steel-framed structure with a concrete slab-on-grade. It is our understanding that the finished floor elevation will be at or near the existing site grades. The site will have access to Parkway Boulevard by a service road entrance along the west side and a parking area will be located on the south side - of the proposed structure. The final location of the proposed building and anticipated building loads were not provided to ATEC prior to the submission of this report. 3.0 GENERAL SUBSURFACE CONDITIONS The subsurface conditions at the site were investigated by reviewing the available published information for the site geologic characteristics and by drilling eight test borings at the locations shown on the Boring Location Plan, Figure 1 in the Appendix. Shelby tube and standard penetration samples were obtained in the clayey soil strata. The underlying shale bedrock was cored at two locations using conventional NX sized rock coring equipment and also tested using Texas Highway Penetration Test methods. Further discussion on the test borings can be found in Section 3.2 of this report. - 2 3.1 General Area Geology According to regional geologic information, the site for the proposed police station is situated near the contact between the Cre_taceou_~__~s age E,agle Ford Group and the .Woodbine.Formation. The Eagle Ford Group consists primarily of interbedded shales - and limestones and has a thickness of 200 to 300 feet in the site area and serves as a confining layer over the water-bearing Woodbine Formation. The Woodbine Formation - has a thickness of 175 to 250 feet and is composed of well sorted sands, clays, sandstones and shale layers. The residual overburden soils typically consist of tan, - brown, and dark gray plastic clays. - 3.2 Soil Profile - In general, within the maximum 29-foot depth explored, the subsurface materials were found to consist primarily of natural clayey soils underlain by gray shale of the Eagle - Ford Shale Formation. The upper natural clay soils are residual materials derived from prolonged weathering of the gray shale bedrock. The general stratigraphy and characteristics of the soil and rock materials encountered within the test borings initiated for this exploration are summarized as follows: Depth, feet Description 0 to 2.0 Reddish brown, very stiff, SANDY CLAY Unified Soil Classification: CL _ Moisture Content: 12 % Liquid Limit: 36 Plastic Limit: l& .~ Plasticity Index: - 3 0-2.0 to 18.0 Dark brown, brown, gray and tan, medium stiff to very - stiff, SILTY CLAY to CLAY Unified Soil Classification: CL-CH Moisture Content: 11 to 30% - Liquid Limit: 40 to 55 Plastic Limit: 19 to 21 Plasticity Index: ~ - Unconfined Compressive Strength: 0.9 to 1.7 tons/ft2 - 18.0 to 19.0-26.0 Dark gray, hard, SHALY CLAY Unified Soil Classification: CH Moisture Content: 22 % 19.0-26.0 to boring Dark gray SHALE termination depths Moisture Content: 5 to 16% Texas Highway Department Penetration Tests: 1.5 inches to 2.5 inches penetration per 100 blows ._. Unconfined Compressive Strength: 10.1 to 24.2 tons/ft2 Based on the test results and our experience in the site area, the upper clay soils at the site are regarded as moderate to highly plastic and potentially moderately to highly expansive. 3.3 Groundwater Conditions Continuous flight augers were used to advance the test borings to the top of the gray shale formation. During the drilling of the borings initiated for this investigation, groundwater was observed on the drilling tools in the soils above the shale strata at depths ranging from 13 to 15 feet below the ground surface. NX rock core drilling techniques were performed to sample the shale in two of the ~test borings. Due to the use of water in the rock coring applications, an accurate measurement of the gr_..oundwater level could not be comp!eted ,after the rock coring activities in those particular borings. Upon completion of test borings and prior to beginning rock coring activities, the groundwater level was measured at depths ranging from 8.5 to 18 feet _ below the ground surface. The borings drilled for this study were backfilled with the drill cuttings immediately upon completion. ,~~ L___oonger ter~readings would require a cased observation w. ell. This ~was not ._ included within the scope of this study. Generally, groundwater flow usually occurs through the clay fissures/joints encountered above the gray shale bedrock. The .... groundwater level at the site is anticipated to fluctuate seasonally depending on the amount of rainfall, prevailing weather conditions and subsurface drainage characteristics. Further details concerning the subsurface materials and groundwater conditions encountered can be obtained from the laboratory test results and boring logs included in the Appendix of this report. 4.0 DESIGN RECOMMENDATIONS The following design recommendations have been developed on the basis of the previously described project characteristics and subsurface conditions. If there is any change in the project criteria, a review should be made by this office to determine if modifications in the recommendations will be required. 4.1 General Considerations The upper clay soils encountered at the site were found to be rarely.to highly pl and are considere ghly e Additionally, these soils were found to have natural moisture contents slightly below to above their respective plastic limits and a consistency of medium stiff to very stiff. These soils are~ience vertical movements as a result of soil moistur~e~...~ch are anticipated beneath areas of the site cov~e~the proposed ~ui!ding Based on the depths of the clays, the plasticity indices, the moisture contents, and the laboratory free swell results of the soils tested, it is estimated that a total potential vertical rise (PVR) of up to 2.0 inches or slightly more could occur beneath the proposed building slab if it is constructed at existing grade. Based on the soil conditions encountered within the test borings, we feel that a drilled - straight shaft and grade beam foundation system with shafts bearing in the gray shale is the most suitable foundation system for the proposed police station structure. - Recommendations for a drilled shaft foundation system are given in Section 4.2 of this report. Typically, it has been ATEC's experience that the ground supported floor slab for police - station structures are designed to withstand a total vertical movement of 1 inch or less. Therefore, we feel that the soil related movements as described previously after grading are excessive for consideration of slab-on-grade construction at this site unless significant improvement of the underlying soils is performed. The only 100% positive method for constructing the floor slab and insuring against damage from swelling of the underlying soils would be to structurally support or suspend the floor slab on the drilled shaft and grade beam foundation system. A suspended floor slab involves structurally connecting grade beams directly beneath the floor slab to the drilled shafts. These drilled shafts would therefore support the weight of the floor slab and the entire building. Furthermore, the floor slab would not be in contact with the expansive clays, therefore, eliminating post construction movement due to such soils swelling. Recommendations for a suspended floor slab are included in Section 4.3 of this report. As an alternative, a less positive way of constructing the floor slab system for the proposed building in which the owner accepts the risk of soil movement occurring below the slab is to construct a floor slab on improved subgrade. As stated previously, we anticipate potential vertical movements of up to 2.0 inches or more could occur below the floor slab after grading has occurred. - 6 In order to reduce the swell potential and variability of the soil conditions beneath the _ proposed police station location, special site improvements must be performed beneath the floor slab to reduce the potential vertical movements to 1 inch or less. The special _ site improvements would begin by excavating the existing moderate to hig~lay soil beneath the building pad area to a specified depth. The resulting excavation should _ then be backfilled with well c. ompacted select fill brought jn__from off si_t,e. Based on our calculations, the depth of select fill beneath the finished subgrade elevation to reduce the _ potential vertical rise movement to 1 inch or less is approximately 3 feet in the area of the proposed police station structure. Recommendations for a floor slab on improved -. subgrade are provided in Section 4.4 of this report. -. 4.2 Drilled Straight Shaft and Grade Beam Foundation System - Once the site grading operations are complete, our findings indicate that the structural frame and walls for the proposed police station can best be supported by a system of - drilled straight shafts. Following are our recommendations for the design of drilled straight shaft foundations. 4.2.1 General Design Considerations In order to develop the full load transfer capacity of the drilled shafts, they should be brought to bear at least 2 feet into the underlying shale bedrock for bearing capacity purposes. It is anticipated that the gray shale will be encountered at depths ranging from approximately 19 to 26 feet below the existing grade. It is also anticipated that the required design shaft depths will penetrate below the minimum depth of 2 feet into the gray shale for larger column loads in order to develop the total load transfer using a combination of end bearing and skin friction. We recommend that the shafts be dimensioned based on a net allowable end bearing pressure of 20 kips/square foot and a skin friction value of 2.7 kips/square foot for downward loads. The skin friction - 7 component should only be applied to that portion of the shaft bearing in the gray shale _ (neglecting the upper 2 feet of penetration). _ These design values were determined from the Texas Highway Penetration Test results obtained and the unconfined compressive strength tests performed on selected samples _ of the gray shale bedrock samples obtained during this exploration. The design values allow for discontinuities and thin clayey seams. The design end beating pressure - additionally applies to shafts that maintain a minimum total length to diameter ratio of 2.5 times. Additionally, we recommend a minimum center to center shaft spacing of at -- least 2.5 times the shaft diameter or reductions in the allowable design values will be required. During installation of the shafts, the cross section of the shafts should not be allOwed to -- increase at the ground level. A "mushroom" at the top of the shafts could create uplift pressures related to soil swelling which could be detrimental to the shafts at some -- locations. Any shaft caps over expansive clays, if required, should be constructed over a void space. Also, all grade beams constructed over clays should be formed with a -- nominal 6-inch void with soil retainers using cardboard box forms or other equivalent materials made for this purpose. The purpose of this void is to minimize uplift pressures on the grade beams from the underlying expansive soils. On-site soils can be used to backfill around perimeter grade beams shortly after removing concrete forms. The backfill should be well compacted to prevent water from entering the void space during or after construction and inducing swelling of the underlying soils. The approximate depth to the shale bedrock should only be used to estimate the shaft bearing depths at the boring locations. The actual bearing depths must be determined based on the design loads and uplift pressures and be confirmed by inspection during construction as will be discussed in Section 5.2. Greater penetration into the gray shale may be required if the upper surface of this stratum is observed to be fractured, broken or weathered. Additionally, if any gray clay or weathered seams are observed during - 8 the drilling operations within the gray shale, the shaft depths should be extended a _ minimum 2 feet beyond these weaker zones before beginning the required penetration. Provided the shafts are designed as outlined above, total settlement beneath properly constructed foundation elements is estimated to be minor, generally on the order of 0.25 inch or less. Such settlement normally occurs as elastic deformation during construction. 4.2.2 Uplift Considerations - Based on our understanding of the proposed grading scheme and depending on the soil and rock conditions below the proposed floor elevation, the drilled shafts will need to be - designed to accommodate uplift pressures due to potentially expansive soil conditions. Swelling clay soils in contact with the shaft perimeters will cause such uplift pressures - to develop in upward skin friction. -- The magnitude of uplift pressure due to soil swell along the shafts is estimated not to exceed 1.0 kip/square foot. The soil swell pressure should generally act over the portion - of the shaft bearing in the soils located to a depth of 10 feet below the final exterior grade. If the slab on improved subgrade alternative is chosen, the uplift pressure can be - reduced to 0.75 kip/square foot acting over the same 10 feet below the final exterior grade. This alternative is discussed in Section 4.4 of this report. All shafts should be adequately reinforced due to uplift pressures caused by either potential swelling soils and/or structural loading conditions. Reinforcing steel should extend the full length of the shaft. The uplift resistance of each straight shaft can be computed using an allowable skin friction value of 2.0 kips per square foot for upward loads acting over the portion of the shaft extending below the minimum 2 feet penetration into the gray shale bedrock. - 9 4.3 Suspended Floor Slab System Two methods are available for constructing a suspended floor slab system. These _ included using pan and joist type construction and raising the floor slab well above the underlying expansive soils or using cardboard carton forms to create a void. The most effective suspended slab system is to use the pan-joist type construction -- utilizing either concrete or steel beams. If this system is used, we recommend that the floor slab be suspended at least 12 inches, and preferably more, above final subgrade - elevations. If utility lines are suspended beneath the slab, the void space clearance should be increased to a minimum of 2 feet to provide for access to these lines. Future - movements of soil supported utility lines must be considered when designing connections, especially where these lines approach or enter the stationary structure. Provisions should -- be made for positive drainage of the under-floor space. Construction with metal beams and joists must also contain sufficient ventilation to limit corrosion of the metal - components. Precast concrete segments spanning between grade beams may also be considered. Cardboard carton forms may also be used to create the void beneath the slab. If these forms are used, care must be taken to preserve their structural integrity and ability to create a consistent void. A rigid material layer should be placed directly on the forms to prevent puncture by personnel during placement of concrete. This rigid layer would also help reduce the potential for concrete to leak down between the cardboard forms. A qualified inspector should be present during floor-slab concrete placement to assure the void is maintained. 4.4 Floor Slab on Improved Subgrade As stated in Section 4.1, due to the presence of moderate to highly expansive clay soils present within the proposed construction area, the proposed new police station will be - 10 subjected to upwards of 2.0 inches or more of potential vertical movement. To achieve _ a total potential vertical movement desirable design level of 1 inch or less, and to keep differential movements to 75 percent or less of the total movement, the following _ subgrade improvements must be accomplished: _ 1) Existing vegetation should be stripped and removed from the site. 2) The building area should be excavated as necessary to a min(mu.m depth ~_ of 3 fe._.~g[~elo~the finished floor slab subgrade elevation. The highly plastic clay soils excavated should be removed from the site, or stockpiled on the site for use as grade raise fill outside the building area. 3) Following excavation and prior to placing fill, the entire subgrade should be inspected. The proofrolling operation should be - performed in accordance with the recommendations provided in Section 5.1. - 4) Following proofrolling, the exposed subgrade clay soils should be scarified to a depth o._ff 6 inches, wetted to within + 3% of optimum moisture content and co~mpacSed to at least 95 ~ of the Standard maximum ~-- dry density for the subgrade materials (ASTM D-698 Method A). 5) Select fill soil should be used as the final 3 feet of fill within the building -~ area. Select fill should be brought in from off site and placed in 8-inch thick horizontal lift..___s within the building areas, moisture conditioned to within -3 % to +3 % Of-optimum moisture content and compacted to 95 % - of the Standard maximum dry density for the select fill materials. Select fill should be placed in accordance with the recommendations outlined in Section 5.3. 6) Filling should then proceed up to finished subfloor grade. The exposed surface of the select fill soils should be kept moist during shaft drilling operations and be moistened just prior to placing the floor slab. The horizontal limits of select fill should be limited to those areas where a reduction in potential soil movements is desired. These may include paving and flatwork areas directly adjacent to the structures such as at doorways and entrances. The select fill should not extend outside the limits of the building in areas which will not be sealed with flatwork or pavement. Additional recommendations regarding select fill below grade are _ provided in Section 5.3 of this report. _ When constructing select fill, care should be taken to avoid water ponding in the select fill layer. This could cause post construction movements which exceed the estimated _ values. Ca._re must b~ee taken to prevent landsca e wateri rface drainage~ leaking utility lines or other sources of water from entering the select fi . We also recommend that the slab-on-grade be "floating", that is, fully ground supported - and not structurally connected to walls or foundation where possible. This will help to minimize the possibility of cracking and displacement of the slab due to differential -~ movement between the slab and the foundation. Although movements are estimated to be within tolerable limits for structural safety, such movements could be detrimental to a slab-on-grade if it is rigidly connected to the foundation system. There may be certain areas or projects where it will be difficult or impractical to make the slab floating. In such areas or on such projects, it may be necessary to increase the slab thickness and reinforcement to prevent the foundations from cracking the slab and moving independently. The project structural engineer should be involved in determining whether a floor slab of this type should be used. A thin sand cus~h, jo~n should be placed below the slab to allow proper curing of the floor slab concrete. In~add(t!.on, a vapor barrier of polyethylene sh_eeting or similar material should be placed between the sand cushion and subgrade soils to retard moisture migration. 4.5 Pavement Subgrade Preparation and Pavement Design We anticipate that once the site grading is complete, moderate to highl~ expansive'clay ) soils will be exposed at the surface on the majority of the site outside the building area. Because these soils exhibit a potential for shrinking and swelling, it is likely that pavements constructed on-site will be subject to movement from the soils below. The - 12 result of these movements causes distress within the pavement section which typically _ leads to higher maintenance frequency and costs than for pavements constructed over non-expansive clays. Some differential movements of the expansive subgrade soils should be anticipated once _ grading is completed. Therefore, the pavement surfaces should be finished and sloped for positive drainage. Good perimeter drainage around the pavements is also -.- recommended. Both total and differential movements should be taken into consideration at locations where pavements transition into structures. Generally, it is common practice t4me stabilize the upper 6 to 8 inches of subgrade s'~ .~th pavements within th~he purpose of this stabilization is not to reduce the movements beneath the pavements, but instead to improve the bearing value of the pavement subgrade soils and provide uniform soil conditions on which to construct the pavements. To reduce the movements beneath the pavement areas generally requires additional pavement subgrade preparation in conjunction with the pavement design. For this project, it is recommended that once the final grade has been established, representative samples of the subgrade materials be obtained for laboratory testing. Lim..____¢ - seri_~es~tests should, be performed on the soil~de4cr, m~e th~lime conc.....~entration to reduce the Plasticity Index t ~5 ro b__el~levels_ to a minimum of 12.4. The exposed surface of the soils should be scarified to a depth of at least 6 inches and mixed with the required amount of lime (determined in the lime - series tests) in accordance with the procedures described in the Standard Specifications for Public Works Construction, North Central Texas, Item 4.6, prepared by the North Central Texas Council of Governments (NCTCOG). The sealed soil-lime mixture should be allowed to cure for a minimum time of 48 hours, then be remixed. The remixing and - 13 pulverization operation, as described in NCTCOG Item 4.6, should proceed until the soil is uniformly broken down and meets the gradation limits provided in that specification. _ The resulting mixture should then be brought to near optimum (optimum to plus 3 percentage points above) moisture condition and uniformly compacted to a minimum of ~ of standard Proctor (ASTM D-698)d~The compacted material should then be covered immediately with paving or kept moist until the paving is placed. In all areas where hydrated lime is used to stabilize the subgrade soils, routine gradation _ tests should be performed at a rate of one test every 10,000 square feet of paving area and at least one test per day. Gradation percentages outlined in NCTCOG Item 4.6 - should be utilized. These tests will confirm that the material has been adequately broken down. Should any areas be out of conformance on these tests, then additional lime or - remixing must be performed to bring the soil into compliance for the 10,000 square feet area represented by the deficient tests. Field density testing should also be performed -~ at the above recommended frequency to confirm proper compaction. - The following reinforced concrete pavement sections have been developed based on the noted traffic loading conditions for consideration at this site. Light Traffic (automobiles, occasional light trucks, parking areas) 5.0 in. Reinforced concrete (3,000 psi concrete) 6.0 in. Lime stabilized and compacted subgrade Heavy Traffic (fire lanes and service drives) _ /,,,,,~t-~6 ~h:~n Reinforced concrete (3,600 psi concrete) Lime stabilized and compacted subgrade A relatively close joint spacing of 15 feet is preferred. Local area practice often includes the use of No. 3 reinforcing steel bars in each direction at spacing of 12 to 24 inches with an 18-inch spacing being commonly used. Expansion joints should be sawed as soon as the concrete will allow. If construction _ joints are provided, these joints should be keyed. Proper design and sealing of joints will help minimize moisture in-flow in the subgrade. A properly graded and drained -. pavement subgrade to minimize the trapping of water under the pavement must also be provided. Proper concrete finishing and curing practices must be employed. All paving - materials should comply with the Texas Department of Transportation Standard Specifications for Construction of Highways, Streets and Bridges, Item 360, 1993. - Loading (traffic) must not be allowed until the concrete has reached 75 percent of its design strength. The pavement sections described above are considered suitable for general purpose usage for the anticipated subgrade conditions. A comprehensive analysis of the pavement system was not within the scope of work for this exploration. This analysis would include consideration of traffic loads, frequency, subgrade drainage, design life and the overall economics. An aggressive maintenance program to keep joints and cracks sealed to prevent moisture infiltration will help extend the pavement life. 4.6 Drainage Positive surface drainage must be incorporated into the final grading plan to reduce seasonal variations in moisture content of the foundation soils. All pavements and sidewalks must be sloped away from the proposed building to prevent ponding of water near the foundations. The foundation slab should be set at a high enough level to permit a final exterior downward grade slope of at least 1 foot (vertical) to 10 feet (horizontal) for a distance of at least 5 feet (but preferably 10 feet) away from the building. Roof downspouts should discharge at least 3 feet away from the foundation slab. __ We recommend that area paving or exterior flatwork extend to the building lines, if possible, rather than have planters or other open areas adjacent to the structure. If _ planters are located adjacent to the building, they should be self-contained to eliminate a possible source of moisture gain or loss to the soils beneath the building slab. All trees should be a minimum of one-half their mature height away from the building or pavement edges to reduce potential for moisture fluctuations in the foundation soils. Careful control of irrigation water within planters is essential. No water must be allowed to percolate down to any remaining underlying potentially active soils below the building. Therefore, we recommend that the exposed backfill soils extending beyond the building lines be capped with a 18 inch thick cover of well compacted, impervious clay with a plasticity index between 15 and 25 or be covered with pavements. The purpose of the - clay cap or pavements is to minimize potential moisture losses or gains beneath the building. 5.0 GENERAL CONSTRUCTION PROCEDURES AND RECOMMENDATIONS It is possible that variation in subsurface conditions will be encountered during construction. In order to permit correlation during construction between the test boring data and the actual subsurface conditions encountered during construction, it is recommended that a registered geotechnical engineer or his representative be retained on a continuing basis to perform observations during construction. Some construction problems, particularly as to degree or magnitude, cannot be anticipated until the course of construction. The recommendations offered in the following paragraphs are not intended to limit or preclude conceivable solutions, but rather to provide the client with our - 16 observations based on our experience and our understanding of the project characteristics and subsurface conditions. 5.1 Site Preparation and Grading _ In general, site preparation should include necessary stripping of vegetation and fencing and proofrolling. Upon completion of excavation and prior to placing any fill, we recommend that the exposed subgrade be carefully inspected by proofrolling to help compact pockets of loose soil and expose additional areas of weak, soft, or wet soils. - This must be accomplished prior to placing any grade raise fill and drilling any shafts. The proofrolling operation must be performed under the observation of a qualified geotechnical engineer. Proofrolling consists of rolling the entire subgrade with a heavily loaded tandem axle dump truck or other approved equipment capable of applying similar wheel loads. Any soft, wet or weak fill or natural soils disclosed by proofrolling should be removed and replaced with well compacted material as outlined in Section 5.3. Care should be exercised during the grading operations at the site. The traffic of heavy equipment, including heavy compaction equipment, may create a general deterioration of the shallower soils. Therefore, it should be anticipated that some construction difficulties could be encountered during periods when these soils are saturated and that it may be necessary to improve, remove or simply stay off of the saturated soils. 5.2 Drilled Shaft Excavations All drilled shaft excavations must be carefully observed to confirm that foundations will bear on satisfactory materials. Materials exposed in the base of all satisfactory shaft excavations should be protected against any detrimental change in condition. Surface runoff water should be drained away from the drilled shaft excavations and not be allowed to collect. All concrete for drilled shafts should be placed the same day the - 17 excavation is made and not more than 4 hours after completion of drilling. All drilled _ shafts should be at least 1.5 feet in diameter to facilitate clean out of the base and proper observation. Based on the soil and groundwater conditions encountered and our experience in the site vicinity, it is our opinion that temporary casing will be required at nearly all of the drilled shaft locations to control groundwater seepage. Any groundwater within the drilled shafts should be removed by pumping within the casing prior to placing concrete. We also recommend that a tremie pipe be utilized d~ring concrete placement to minimize segregation of aggregates from the concrete. 5.3 Fill Placement and Compaction All soil materials used as fill should be free of decomposable or otherwise deleterious material. All on-site or fill soils with a plasticity index greater than 15 can be used as grade raise fill outside the building area. All clay soils should be compacted to a dry density of at least 93 percent, but not exceeding 98 percent, of the Standard maximum dry density (ASTM D-698 Method A). The compacted moisture content of the clays during placement should be at optimum and not exceeding 6 percentage points above the optimum moisture content. Recommendations for preparation and compaction of soils within the upper 6 inches below the pavement sections are discussed in Section 4.6. Materials brought in from off-site and used as ~beneath the building should consist of a uniform, homogeneous, non-expansive sandy clay or clayey sand soil with a liquid limit (LL) between 20 to 35 and have a t/lasticity index (PI) of not~ss~th~in 5~ or [g~ater than 15.)All select fill should be moisture processed within -3 to +3 percentage points of the materials optimum moisture content and ~ompa~cted'~o a dry density of at lea f the Standard maximum dry density. Compaction should be accomplished by placing the fill in 6 to 8 inch thick loose lifts and compacting each lift to at least the specified minimum dry density. It is imperative that the fill materials not exceed four inches in maximum size. If larger fragments or clods are encountered during grading, then these clods must be broken down prior to final placement and compaction in the fill. In order for the fill materials to perform as intended, the fill material must be placed in a manner which produces a good uniform fill compacted within the density and moisture ranges outlined in the preceding paragraphs. Density testing must be performed on fill soils to confirm this performance as construction progresses. In the building area fills, we recommend that each lift be tested at a frequency of no less than 1 test per lift per each 5,000 square feet. In remaining areas on-site, a testing frequency of 1 test per lift per each 10,000 square feet should be sufficient. As was stated in Section 5.2, we anticipate that temporary shaft casing will be required at nearly all of the drilled shaft locations. It is anticipated that minor groundwater seepage in drilled shaft excavations can be generally handled by temporary casings and conventional dewatering equipment. If shallow groundwater seepage is encountered during placement of select fill or utility trench excavations, the water should be collected at low points in the excavation and then be removed by pumping. 6.0 QUALIFICATIONS OF RECOMMENDATIONS Our evaluation of foundation design and construction conditions has been based on an understanding of the site and project information and data obtained during our field investigation. The general subsurface conditions utilized have been based on interpolation of the subsurface data between the borings. Regardless of the thoroughness of a subsurface investigation, there is always the possibility that conditions between borings will be different from those at the boring locations, that conditions are not as anticipated by the designers, or that the construction _ process has altered the soils conditions. Therefore, experienced geotechnical engineers or their representative should inspect the earthwork and foundation construction to confirm that the conditions anticipated in design actually exist. Otherwise, we assume no responsibility for construction compliance with the design concepts, specifications or recommendations. In our experience, ATEC has found it beneficial that once the final construction plans and specifications have been completed, that we be allowed to review such plans and related documents. The purpose of the review will be to confirm that the design documents and details are consistent with the recommendations included in this report. The design recommendations presented in this report have been developed on the basis of the previously described project characteristics and subsurface conditions. If there is any change in these project criteria, including project location on the site, a review should be made by this office to determine if any modifications in the recommendations will be required. The findings -- of such a review should be presented in a supplemental report. -- The nature and extent of variation between the borings may not become evident until the course of construction. If significant variations then appear evident, it will be necessary to reevaluate the recommendations of this report after performing on-site observations during the construction period and noting the characteristics of any variation. However, only minor variations that can be readily evaluated and adjusted for during construction are expected. Our professional services have been performed, our findings obtained and our recommendations prepared in accordance with generally accepted geotechnical engineering principles and practices. This warranty is in lieu of all other warranties either expressed or implied. This company is not responsible for the conclusions, opinions or recommendations made by others based on these data. As the client of a consulting geatechnical engineer, you MOST GEOTEC. FINICAL FINDINGS ARE -- should know that site subsurface conditions cause more PROFESSIONAL JUDGMENTS construction problems than any other factor. ASFE/T'he Site exploration identifies actual subsurface conditions Association of Engineering Firms Practicing in the only at those points where samples are taken. The data _ Geosciences offers the following suggestions and were extrapolated by your geatechnica[ engineer who observations to help you manage your risks, then applied judgment to render an opinion about overall subsurface conditions. The actual interface A GEOTECHNICAL ENGINEERING REPORT IS BASED between materials may be far more gradual or abrupt ON A UNIQUE SET OF PROJECT-SPECIFIC FACTORS than your report indicates. Actual conditions in areas Your geatechnical engineering report is based on a not sampled may differ from those predicted in your subsurface exploration plan designed to consider a report. While nothing can be done to prevent such unique set of project-specific Factors. These factors situations, you and your geotechnical engineer can work typically include: the general nature of the structure together to help minimize their impact. Retaining your involved, its size, and configuration; the location of the geotechnical engineer to obse.we construction can be structure on the site; other improvements, such as particularly beneficial in this respect. access roads, parking lots, and underground utilities; and the additional risk created by scope-of-service A REPORT'S RECOMMENDATIONS limitations imposed by the client. To help avoid costly CAN ONLY BE PRELIMINARY problems, ask your geatechnical engineer to evaluate The construction recommendations inctuded in your how Factors that change subsequent to the date of the geotechnical engineer's report are preJiminary, because report may affect the report's recommendations, they must be based on the assumption that conditions revealed through selective exploratory sampling are Unless your geotechnical engineer indicates otherwise, indicative of actual conditions throughout a site. do not use your geotechnical engineering report: Because actual subsurface conditions can be discerned only during earthwork, you should retain your geo- - when the nature of the proposed structure is technical engineer to observe actual conditions and to changed, for example, if an office building will be finalize recommendations. Only the geotechnical erected instead of a parking garage, or a re~'dgerated engineer who prepared the report is fully familiar with warehouse will be built instead of an unrefrigerated the background information needed to determine one; whether or not the report's recommendations are valid · when the size. elevation, or configuration of the and whether or not the contractor is abiding by'appli- proposed structure is altered; cable recommendations. The geotechnical engineer who · when the location or orientation o1: the proposed developed your report cannot assume responsibility or structure is modified; liability for the adequae/of the report's recommenda- · when there is a change of ownership; or tions if another party is retained to observe construction. · for application to an adiacent site. GEOTECHNICAJ. SERVICES ARE PERFORMED Geotechnical engineers cannot accept responsibility for FOR SPECIFIC PURPOSES AND PERSONS problems that may occur if they are not consulted after Consulting geotechnical engineers prepare reports to Factors considered in their report's development have meet the specific needs of specific individuals. A report changed, prepared for a civil engineer may not be adequate for a construction contractor or even another civil engineer. SUBSURFACE CONDITIONS CAN CHANGE Unless indicated otherwise, your geotechnical engineer A geotechnical engineering report is based on condi- prepared your report expressly for you.and expressly for tions that existed at the time of subsurface exploration, purposes you indicated. No one other than you should Do not base construction decisions on a geotechnical apply this report for its intended purpose without first engineering report whose adequacy may have been conferring with the geotechnica! engineer. No party affected by time. Speak with your geotechnical consult- should apply this report for any purpose other than that ant to learn if additional tests are advisable before originaIly contemplated without first conferring with the construction starts. Note. too, that additional tests may geotechnical engineer. be required when subsurface conditions are affected by construction operations at or adiacent to the site, or by GEOENVIRONMENTAL CONCERNS natural events such as floods, earthquakes, or ground ARE NOT AT ISSUE water fluctuations. Keep your geotechnical consultant Your geotechnical engineering report is not likely to apprised of any such events, relate any findings, conclusions, or recommendations about the potential for hazardous materials existing at mates was not one of the specific purposes for which it the site. The equipment, techniques, and personnel was prepared. In other words, while a contractor may used to perform a geoenvironmental exploration differ gain important knowledge from a report prepared for substantially from those applied in geotechnical another pa~'y, the contractor would be well-advised to engineering. Contamination can ceate maior risks. If discuss the report with your geotechnical engineer and you have no information about the potential for your to perform the additional or alternative work that the site being contaminated, you are advised to speak with contractor beIieves may be needed to obtain the data your geotechnical consultant for information relating to specifically appropriate for construction cost estimating teoenvironmental issues, purposes.) Some clients believe that it is unwise or unnecessary to give contractors access to their gea- A GEOTECHNICAL ENGINF. F.~NG [~PORT IS technical engineering reports because they hold the SUBJECT TO MISINTEI~,PRETATION mistaken impression that simply disclaiming responsi- Cosdy problems can occur when other design profes- bility for the accuracy of subsurface information always sionals develop their plans based on misinterpretations insulates them from attendant liability. Providing the ora geotechnical engineering report. To help avoid best available information to contractors heips prevent misinterpretations, retain your geotechnical engineer to cosdy construction problems. It also hetps reduce the work with other project desii~n professionals who are adversarial attitudes that can aggravate problems to affected by the ~,eatechnical report. Have your geotech- disproportionate scale. nical engineer explain report implications to design professionals affected by them, and then review those ~ RESPONSIBILITY CLAUSES CLOSELY design professionals' plans and specifications to see Because ~eotechnical engineerin~ [s based extensive!y how they have incorporated ~eotechnical factors, on judgment and opinion, it is far less exact than other Although certain other design professionals may be lam- design disciplines. This situation has resulted in whoily iliar with geotechnica[ concerns, none knows as much unwarranted claims being lodged against ~eotechnical about them as a competent geotechnical engineer, engineers. To heip prevent this problem, geotechnicat engineers have developed a number of clauses for use in BORJNG LOGS SHOULD NOT BE SEPARATED their contracts, reports, and other documents. Respansi- FROM THE REPORT bility douses are nat exculpatory clauses designed to Geotechnical engineers develop final bodng logs based transfer geotechnical engineers' liabilities to other upon their interpretation of the fieid logs (assembled by parties. Instead. they are definitive clauses that identi~ site personnel) and laboratory evaluation of field where ~eotechnical engineers' responsibilities begin and samples. Geotechnical engineers customarily include end. Their use helps all parties involved recognize their only final boring logs in their reports. Final bodng logs individual responsibilities and take appropriate action. should not under any circumstances be redrawn for Some of these definitive clauses are likely to appear in inclusion in architectural or other design drawings, your geotechnical engineering report. Read them because drafters may commit errors or omissions in the ctosety. Your geotechnical engineer will be pleased to transfer process. Although photographic reproduction give full and frank answers to any questions. eliminates this problem, it does nothing to minimize the possibility of contractors misinterpreting the logs during P. ELY ON THE GEOTECHN1CAL ENGINEER bid preparation. When this occurs, delays, disputes, and FOR ADDITIONAL ASSISTANCE unanticipated costs are the all-too4requent result. Most ASFE-member consulting geotechnical engineer- ing firms are familiar with a variety of techniques and To minimize bhe likelihood of bodng log misinterpreta- approaches that can be used to help reduce dsks for all tion. give contractors ready access to the complete parties to a construction project, from design through geotechnical engineedn~ report prepared or authorized construction. Speak with your ~eotechnical engineer not for their use. Iff access is provided only to the report only about geotechnical issues, but others as well. to prepared for you, you should advise contractors of the learn about approaches that may be of genuine benefit. report's limitations, assuming that a contractor was not You may also wish to obtain certain ASFE publications. one of the specific persons for whom the report was Contact a member of ASFE of ASFE for a complimentary prepared and that developing construction cos~: esti- director/of ASFE publications. PROFESSIONAL FIRMS PIGACTIClNG IN THE GEO$CIENCES _ 881 I COLESVILLE ROAD/SUITE G 106/SILVER SPRING, MD 209 l0 TELEPHONE: 301/565-2733 FACSIMILE: 301/589-201T Co~yni,,ht I qq2 ~y ~,$F--_. Inc Uniess ASF=_ ~rants s~ec~fic ~ef~i~ion ~o dO ~o. duplication a~ :h~s document by any means ~ha~soever ~s e~ressly ~roh,b[~ed Re-useof~he ~cr~in~ n :h~sdocument. m'~hole;rm~a~ also~se.~Dr~s$lyprohibi~ed and ma',' be done cn~) ~t~ ~hee~cress=erm~ss~onofA~F~or~or=ur;os~s o~ revle,~ or scholarly roseate* B PCOSg 2.~'~ ~M APPENDIX Figure 1 - Boring Location Plan Field Investigation Procedures Laboratory Investigation Procedures Table 1 - Free Swell Test Results Table 2 - Unconfined Compressive Strength Test Results on Gray Shale Specimens Record of Subsurface Exploration Sheets (Boring Logs) Key to Soil Symbols and Classification FIELD INVESTIGATION PROCEDURES Using standard continuous flight auger drilling equipment, a total of eight test borings were drilled for this investigation at the approximate locations shown in the Boring Location Plan, Figure 1, included in this Appendix. The number and general location of the borings were chosen by Phillips Swager Associates. The depths of the test borings was determined by ATEC Associates. The test boring locations were staked in the field by an ATEC representative using standard taping procedures. _ Relatively undisturbed samples of the cohesive subsurface materials were obtained by hydraulically pressing 3 inch O.D. thin-wall tubes into the underlying soils at selected depths _ (ASTM D-1587). These samples were removed from the sampling tubes in the field and examined visually. One representative portion of each sample was sealed in a plastic bag for - use in future visual examinations and possible testing in the laboratory. - Representative samples of the subsurface materials were also obtained employing split-spoon sampling procedures (ASTM D-1586). Relatively disturbed samples were obtained at a selected -- depths in the borings by driving a standard 2 inch O.D. split-spoon sampler 18 inches into the subsurface material using a 140 pound hammer falling 30 inches. The number of blows required - to drive the split-spoon sampler the final 12 inches of penetration (N-value) is recorded in the appropriate column of the logs. Samples of the underlying gray shale bedrock were obtained in two of the eight test borings - initiated for this study using conventional NX rock coring equipment and techniques. The rock core samples were retained and transported to our laboratory in appropriate core boxes. Selected core samples were field wrapped for preservation of moisture content. In addition, the underlying gray shale bedrock was tested using Texas Highway Department (THD) cone penetrometer test methods. The cone penetrometer test is performed by driving a 45° metal cone into the bedrock materials using a 140 pound hammer falling 36 inches. The cone is hammered 100 blows and the number of inches of penetration driven is then recorded. This value is provided on the appropriate boring logs. Logs of all borings (Record of Subsurface Exploration Sheets) have been included in this Appendix. The logs show visual descriptions of the soil and rock strata encountered using the Unified Soil Classification System. Sampling information, pertinent field data, and field observations are also included. LABORATORY INVESTIGATION PROCEDURES The soil and rock samples were inspected and classified by a geotechnical engineer in accordance with the Unified Soil Classification System and the boring logs were edited as necessary. Natural moisture content tests (ASTM D-2216) and Atterberg limit tests (ASTM D-4318) were _ performed on selected samples to aid in classifying the subsurface materials and to determine the engineering characteristics of the materials. In addition, hand penetrometer strength tests _ were performed on selected soil samples. Results of all laboratory tests described above are provided on the accompanying boring logs. The expansive properties of the upper clay layer was further analyzed by performing a free swell - test. The free swell test was performed by placing a selected sample in the consolidometer apparatus with a predetermined overburden pressure and allowing the sample to expand by - absorbing water. When the sample exhibits very little tendency for further expansion, the final height was recorded and the percent swell and total moisture gain calculated. The result of this .... test is listed in Table I in this Appendix. Unconfined compressive strength tests were performed on selected rock core samples in accordance with ASTM Method D-2983-86 in order to evaluate the allowable end bearing and - skin friction design values for the gray sandy shale bedrock. The results of these tests are listed in Table 2 in this Appendix and on the accompanying boring logs. GEOTECHNICAL EXPLORATION PROPOSED POLICE STATION -- Parkway Boulevard Coppell, Texas 25-02-95-00092 Overburden Initial Final Free Boring Depth, (ft) Pressure, (tsf) Moisture, {'%) Moisture, {'%) Swell, I'%) - B-3 [ 2-4 0.191121.4122.7 1.0 Moisture Unconfined Compressive Boring Depth, (ft) Content, (%) Strength, (tsf) B-1 19.5 - 20.5 13 17.5 B-1 25 - 26 13 10.1 B-4 21 - 22 5 24.2 B-4 25 - 26 16 23.1 _ ATEC Associates, Inc. r 11356 Mathis Avenue RECORD OF Dallas, Texas 75229 (214) 558-2204 SUBSURFACE EXPLORATION Metro 263-1681 Client City of Coppell Boring # B-1 (Page 1 of 1) Architect Engineer Job # 25-02-95-00092 -* Project Name PROPOSED POLICE STATION Drawn By SS/CRF Project Location Parkway Boulevard/Coppell, Texas Approved By DPZ DRILLING end SAMPENG INFORMATION TEST DATA -- Date Started 4-28-95 Hammer Wt. N/A lbs. Date Completed 4'28-95 Hammer Orop N/A in. ~ Drill Foremen RDC Spoon Sampler OD NIA in. ~' ~*; -- Inspector Rook Core Dia. 2.125 in. = o ,. Boring Method CFA Shelby Tube OD 3.0 in. ~ ~ ; = o'o ClientlD# 0151 Continuoua Tube OD N/A in. ~->' ;~ ~-.° =~ ~° ~ ~' o -=-'='- -- SOILsuRFAcECLASSIFICATIONELEVATiON ' ~E ,,,~ ~¢(~ ~ ~' o~ '~ ~c~° ~ _c.5=°°~~°=~° ~' = '~ ~ ~ ##= (J. _. Dark brown, stiff, SILTY CLAY to - CLAY(CL. CH) - ~ ST 60 1.5/2.C 16.0 _ _~ -stiff tO very stiff with trace sand _ below 1' _ - -very stiff below 2' - 2 !sm 60 2.25 18.0 46 -medium stiff to stiff with trace sand - below 4' 5 3 ST 60 1.0 19.0 -dark gray with trace calcareous - ._ - deposits below 8' _ 4 ST 100 1.0 1.0 105.7 24.0 _ 10 -tan and gray with gravel below 13' _~----- - -- 5 ST 1.0 13.0 - Dark gray, hard, SHALY CLAY (CH) 19.0 6 ST 70 4.5+ 20 - _ 7 RC 89 - 25 66 10.1 137.6 13.0 Bottom of boring at 29' SAMPLER TYPE GROUNDWATER DEPTH BORING METHOD -- SS - SPLIT SPOON-SPT _~ AT COMPLETION 16.00 FT. HSA- HOLLOW STEM AUGER ST - PRESSED SHELBY TUBE ~[ AFTER HRS. FT. CFA- CONTINUOUS FMGHT AUGERS RC - ROCK CORE ~ WATER ON RODS 13.00 FT. DC - DRIVING CASING THD - TEXAS HIGHWAY DEPARTMENT CONE 'J' AT SURVEY FT. RW - ROTARY WASH CU - CUTTINGS HPA- HAND POWER AUGER -' CT - CONTINUOUS TUBE _ ATEC Associates, Inc. V 11356 Mathis Avenue RECORD OF Dallas, Texas 75229 {214) 556-2204 SUBSURFACE EXPLORATION Metro 263-1681 Client City of Coppell Boring # B-2 (Page 1 of 1) Architm=t Engineer Job # 25-02-95-00092 -- Project Name PROPOSED POLICE STATION Drawn By SS/CRF Projm3t Location Parkway Boulevard/Coppell, Texas Approved By DPZ DRILENG and SAMPLING INFORMATION TEST DATA _ Date Started 4-28-95 Hemmer Wt. N/A lbs. Date Completed 4-28-95 Hammer Drop N/A in. Drill Foremen RDC Spoon Sampler OD 2.0 in. i- .> -- Inspector Rock Core Di~. N/A in. Client ID # 0151 Continuous Tube OD N/A in. ~-. ~-- ! · ~- '5=='- SOIL CLASSIFICATION E ~ ~ " --~ 8 .z o ,c ~ o ~ -~" ~. SURFACE ELEVATION ' .~ _c., = _ ; Dark brown, stiff to very stiff, SILTY -- CLAy to CLAY (CL-CH) - 1 ST 80 2.0 2O.O ss =~ 34_ -very stiff with trace calcareous - - deposits below 2' _ 2 ST 80 2.5 23.0 - -stiff below 4' - 5 3 ST 70 1.5 - -brownish gray, stiff to Yery stiff ~ ~ - _ - below 8' _ 4 ST - 1.7 2.o 109.3 19.0 _ -tan and gray, medium stiff to stiff - - with gravel below 13' _ 5 ~._.J.~. 0.9 1.0 119.4 ~4.0 _ ~ 18.0 - -D~-k-g-r~y~ hard, SHALY CLAY (CH) - -- __ 6 ST 90 4.5+ 22.0 _ 20 _ · SS 90 ~0/4.5' _ 25 _ 26.0 -- Dark gray SHALE __ 8 THD 0011.5 Bottom of boring at 29' SAMPLER TYPE GROUNDWATER DEPTH BORING METHOD -- SS - SPLIT SPOON-SPT =~ AT COMPLETION 8.50 FT. HSA- HOLLOW STEM AUGER ST - PRESSED SHELBY TUBE _~ AFTER HRS. a.oo FT. CFA- CONTINUOUS FMGHT AUGERS RC - ROCK CORE · WATER ON RODS 15.00 FT. DC - DRIVING CASING THD - TEXAS HIGHWAY DEPARTMENT CONE -{- AT SURVEY FT. RW - ROTARY WASH CU - CUTTINGS HPA- HAND POWER AUGER CT - CONTINUOUS TUBE _ ATEC Associates, Inc. V 11356 Math[~ Avenue RECORD OF Dallaa, Texaa 75229 (214) 556-2204 SUBSURFACE EXPLORATION Metro 263-1681 C~ient City of Coppell Boring # B-3 (Page 1 of 1) Arohiteot Engineer Job # 25-02-95-00092 -- Proieet Name PROPOSED POLICE STATION Drawn By SS/CRF Project Lo~ation Parkway Boulevard/Coooell. Texas Approved By. DPZ DRILLING and SAMPMNG INFORMATION TEST DATA Date Started 4-28-95 Hammer Wt. 140 lbs. Date Completed 4-28-95 Hammer Drop 30 in. ~ · Drill Foreman RDC Spoon Sampler OD 2.0 in. ~ e- Boring Shelby Tube OD in. ,~"' i ~ Client ID # 0151 Continuous Tube OD NIA in. ~ · SOIL CLASSIFICATION E ~ ~ ~o = ~ ~ ._== ~_ o I,- SURFACE ELEVATION' aa' ~ O_' ~ ~' =~ ~ c,, =° ~ . '~ POSSIBLE FILL, Dark to reddish brown, -- - very stiff, SANDY CLAY (CL) - 1 ST 40 3.25 12.0 _ 2.0 Dark brown, very stiff, SILTY CLAY to - CLAY (CL-CH) - 2 ST 5O 3.0 21.0 -stiff tO very stiff below 4' 5 3 ST 50 2.0 26.0 -gray, stiff, with trace calcareous - _ - nodules below 8' _ 4 ST 50 1.5 -- 10 - -light brown and gray with gravel ._~ ~ - - below 13' .--=__ ~T 7o ! 1.2 1.5 ~ 26.314.0 - -- -- 18.0 _ b~Fk-g-r~y~ hSr-d7 ,~1~1~,£~7 eLAY (CH) _ 6 SS !10(~ ~5tl 1 -- 20 _ 23.0 -- Dark gray SHALE Bottom of boring at 25' 25 7 rHD 00/2.5 SAMPLER TYPE GROUNDWATER DEPTH BORING METHOD -- SS - SPLIT SPOON-SPT _~ AT COMPLETION 18.20 FT. HSA- HOLLOW STEM AUGER ST - PRESSED SHELBY TUBE ~ AFTER HRS. 14.10 FT. CFA- CONTINUOUS FLIGHT AUGERS RC - ROCK CORE · WATER ON RODS 15.00 FT. DC - DRIVING CASING THD - TEXAS HIGHWAY DEPARTMENT CONE -I' AT SURVEY FT. RW - ROTARY WASH CU - CUTTINGS HPA- HAND POWER AUGER --- CT - CONTINUOUS TUBE _ ATEC Associates, Inc. V 11356 Mathis Avenue RECORD OF Della., Texas 75229 (214) 556-2204 SUBSURFACE EXPLORATION Metro 263-1681 C~ient City of Coppell Boring # B-4 (Page I of 1) Architect Engineer Job # 25-02-95-00092 -- Project Name PROPOSED POLICE STATION Drawn By SS/CRF Project Location Parkway Boulevard/Coppell, Texas Approved By DPZ DRILLING end SAMPLING INFORMATION TEST 0ATA Date Started 5-2-95 Hammer Wt. N/A lbs. Date Completed 5'2-95 Hammer Drop N/A in. Drill Foremen RDC Spoon Sampler OD N/A in. -- Inspector Rock Core Dia. 2.125 in. Boring Method (;FA Shelby Tube OD 3.0 in. Client ID # 0151 Continuou. Tube OD N/A in. -- SOIL CLASSIFICATION SURFACE ELEVATION ' Dark brown, stiff, SILTY CLAY to - - CLAY (CL-CH) -very stiff below 2' -stiff to very stiff with trace calcareous deposits below 4' - -brownish gray and stiff below 8' -stiff to very stiff with some gravel - below 13' Dark gray, hard SHALY CLAY (CH) Dark gray SHALE Bottom of boring at 29' SAMPLER TYPE GROUNDWATER DEPTH BORING METHOD SS - SPLIT SPOON-SPT _~ AT COMPLETION 14.40 FT. HSA- HOLLOW STEM AUGER ST - PRESSED SHELBY TUBE ~ AFTER HRS. 13.00 FT. CFA- CONTINUOUS FLIGHT AUGERS RC - ROCK CORE · WATER ON RODS 13.00 FT. DC - DRIVING CASING THD - TEXAS HIGHWAY DEPARTMENT CONE 't- AT SURVEY FT. RW - ROTARY WASH CU - CUTTINGS HPA- HAND POWER AUGER CT - CONTINUOUS TUBE ATEC Associates, Inc. lr 11356 Mathi, Avenue RECORD OF Dallas, Texas 75229 (214) 556-2204 SUBSURFACE EXPLORATION Metro 263-1681 Client City of Coppell Boring # B-5 (Page 1 of 1) Arohiteot Engineer Job # 25-02-95-00092 Projeot N~rna PROPOSED POLICE STATION Drawn By SS/CRF Project Looation Parkway Boulevard/Coppell, Texas Approved By DPZ DRILUNG end SAMPUNG INFORMATION 'TEST DATA Date Started 4-28-95 Hemmer wt. N/A :bs. Date Completed 4-28-95 Hemmer Drop. N/A in. Drill Foreman RDC Spoon Sampler OD N/A in. r- .> Boring Method CFA Shem¥ Tube OD 3.0 in. Client ID # 0151 Continuous Tube OD N/A in. ..~ SOIL CLASSIFICATION E ~ SURFACE ELEVATION' _ Dark brown, very stiff, SILTY CLAY to _ CLAy (CL-CH) - 1 ST SO 2.75 24.0 _ -stiff to very stiff below 2' - -- _ 2 ST 100 2.0 30.0 - -very stiff below 4' 3 ST 100 2.25 Bottom of boring at 5' 5 - (Dry upon completion) - - 10 2O 25 SAMPLER TYPE GROUNDWATER DEPTH BORING METHOD SS - SPLIT SPOON-SPT _~ AT COMPLETION FT. HSA- HOLLOW STEM AUGER ST - PRESSED SHELBY TUBE ~ AFTER HRS. FT. CFA- CONTINUOUS FUGHT AUGERS RC - ROCK CORE · WATER ON RODS FT. DC - DRIVING CASING THD - TEXAS HIGHWAY DEPARTMENT CONE + AT SURVEY FT. RW - ROTARY WASH CU - CUTTINGS HPA- HAND POWER AUGER CT - CONTINUOUS TUBE _ ATEC Associates, Inc. '135B Mathia Aven,,e RECORD OF Dellaa, Texas 75229 (214) 556-2204 SUBSURFACE EXPLORATION Metro 263-1681 Client City of Coppell Boring # B-6 (Page 1 of Architect Engineer Job # 25-02-95-00092 -- Project Name PROPOSED POLICE STATION Drawn By SSICRF Project Lo~ation Parkway Boulevard/Coppell~ Texas Approved By DPZ DRILUNG end SAMPENG INFORMATION TEST DATA _ Date Started 4-28-95 Hammer Wt. N/A lbs. Date Completed 4-28-95 Hammer Drop NIA in. Drill Foremen RDC Spoon Sampler OD N/A in. Inspector Rock Cora Dia. N/A in. -- SOiL CLASSIFICATION E ~, ~ SURFACE ELEVATION ' e~ = ' Dark brown, stiff, SILTY CLAY to -- _ CLAY(CL_CH) - ~ ST lO0 1.5 - -dark brown and tan below 2' _ _ 2 ST 70 1.5 lB.0 - -reddish brown and hard below 4' 3 ST ~00 ~4.5+ 7.O Bottom of boring at 5' 5 _ - (Dry upon completion) - - 10 -- 15 20 25 SAMPLER TYPE GROUNDWATER DEPTH BORING METHOD ~ SS - SPLIT SPOON-SPT _~ AT COMPLETION PT. HSA- HOU.OW STEM AUGER ST - PRESSED SHELBY TUBE ~ AFTER HRS. FT. CFA- CONTINUOUS FUGHT AUGEP~ RC - ROCK CORE ~ WATER ON RODS FT. DC - DRIVING CASING THD - TEXAS HIGHWAY DEPARTMENT CONE 't- AT SURVEY FT. RW - ROTARY WASH CU - CUTTINGS HPA- HAND POWER AUGER .... CT - CONTINUOUS TUBE _ ATEC Associates, Inc. V 11356 Mathis Avenue RECORD OF Dallas, Texaa 75229 (214) 556-2204 SUBSURFACE EXPLORATION _ Metro 263-1681 Client City of CoDDell Boring # B-7 (Page 1 of 1) Amhiteot Engineer Job # 25-02-95-00092 '- Project N~m. PROPOSED POLICE STATION Drawn By ~S/CRF Proj~t Location Parkway Boulevard/Coppell, Texas Approved ay DPZ DRILUNG end SAMPUNG INFORMATION TEST DATA _ Date Started 5-2-95 Hemmer Wt. N/A lbs. Date Completed ~-2-95 Hemmer Drop N/A in. Drill Foreman RDC Spoon Sampler OD N/A in. -- Inspector Rock Core Dia. N/A in. Client ID # 0151 Continuoue Tube OD N/A in. SOIL CLASSIFICATION E ~ SURFACE ELEVATION ~ <~ _ Dark brown, hard, SILTY CLAY to - CLAy (CL-CH) - 1 ST 50 4.5+ 13.0 _ _ - .very stiff below 3' - 2 ST 60 $.012.5 -- -stiff below 4' 3 ST 90 1.5 -- Bottom of boring at 5' 5 - (Dry upon completion) - - 10 - 15 20 25 SAMPLER TYPE GROUNDWATER DEPTH BORING METHOD -- SS - SPLIT SPOON-SPT ~ AT COMPLETION FT. HSA- HOLLOW STEM AUGER ST - PRESSED SHELBY TUBE ~ AFTER HRS. FT. CFA- CONTINUOUS FMGHT AUGERS RC - ROCK CORE · WATER ON RODS FT. DC - DRIVING CASING THD - TEXAS HIGHWAY DEPARTMENT CONE '1' AT SURVEY FT. RW - ROTARY WASH CU - CUTTINGS HPA- HAND POWER AUGER CT - CONTINUOUS TUBE - ATEC Associates, Inc. V 11356 Mathie Avenue RECORD OF Dallas, Texas 75229 (214) 556-2204 SUBSURFACE EXPLORATION _ Metro 263-1681 Client (~it~ of Coppell Boring # B-8 (Page I of 1) Architect Engineer Job # 25-02-95-00092 -- Project Name PROPOSED POLICE STATION Drawn By SS/CRF Project Lo~tion Parkway Boulevard/Coppell, Texas Approved By DPZ DRILLING and SAMPENG INFORMATION TEST DATA _ Date Started 5-2-95 Hammer wt. N/A lbs. oats Comp~ted 5-2'95 Hammer Drop NIA in. Drill Foreman RDC Spoon Sampler OD N/A in. = ~ ~ x --- Inspector Rock Cora Dia. N/A in. Boring Method CFA Shelby Tube OD 3.0 in. Client ID # 0151 Continuous Tube OD N/A in. SOIL CLASSIFICATION ;='=E ~ su.~^CE ~L~V^T~O.' = '= <= =~<~ ~ =~ ~ ~ =; ° ' = ' Dark to light brown, hard, SILTY CLAY - _ to CLAY {CL-CH) - ~ ST ~ 00 4.S + la.0 _ -reddish brown, medium stiff to stiff - -- below 2' __ 2 ST 100 1.0 16.0 - -brownish gray and very stiff below 4' 3 ST ~00 3.5 Bottom of boring at 5' 5 _ - (Dry upon completion) - - 10 -- 15 20 25 SAMPLER TYPE GROUNDWATER DEPTH BORING METHOD -- SS - SPUT SPOON-SPT .~ AT COMPLETION FT. HSA- HOLLOW STEM AUGER ST - PRESSED SHELBY TUBE ~ AFTER HRS. FT. CFA- CONTINUOUS FUGHT AUGERS RC - ROCK CORE ~ WATER ON RODS FT. DC - DRIVING CASING THD - TEXAS HIGHWAY DEPARTMENT CONE '~' AT SURVEY FT. RW - ROTARY WASH CU - CUTTINGS HPA- HAND POWER AUGER CT - CONTINUOUS TUBE ATE¢ KEY TO SOIL SYi~BOI.~ ~ CLA$$11rlC~TION Tim abbreviations commonly employed on each 'Record of Subsurface Exploration' sheet on the figures and in the text of the report are as follows: L SOIL DESCRIPTION V. SOIL PROPERTY SYMBOLS (A) Cohesionless Soils N: Standard Penetration Resistance: number of blows by a 140 lbs. hammer -- ~ ~l. blows/ft, dropped 30 inches required to drive a 2' Very Loose 0 to 4 O.D. split-spoon sample one foot. Loose 5 to 10 Qu: Unconfined compressive strength, tsf -- Medium Dense 11 to 30 Qp: Penetrometer unconfined compressive Dense 31 to 50 strength, tsf Very Dense Over 50 Id: Natural density, pcf _ v: Apparent groundwater level immediately at completion (B) Cohesive Soils ·: Groundwater level several hours after completion of drilling -- Consistency Qu. tsf ·: Water level noted on drilling tools Ve~] Soft ~ ~an 0.25 Mc: Water Content Soft 0.25 to 0.50 LL: Liquid Limit. % _ Medium Stiff 0.50 to 1.00 PL: Plastic Limit. % Stiff 1.00 to 2.00 SL: Shrinkage Limit Very Stiff 2.00 to 4.00 PI: Plasticity Index (LL-PL) Hard Over 4.00 Lh Liquidity Index (Mc-PL/PI) e: Void ratio II. PLASTICITY Gs: Specific gravity of solid particles k: Coefficient of permeability -- Degree of Plasticity i: Hydraulic gradient Plasticity ~ndex q: Rate of discharge None to Slight 0 to 4 h: Hydraulic head or potential _ Slight 5 to I0 Medium 11 to 30 VI. DRILLING AND SAMPLING SYMBOLS Hi/h to Very Hi/h Over 30 AU: Auger Sample -- HI. RELATIVE PROPORTIONS CB: Carbide Bit DB: Diamond Bit __ Trace 1 to 10 except where noted Little 11 to 20 ST: Shelby Tube = 3' O.D. except where Some 21 to 35 noted And 36 to 50 WS: Washed Sample IV. PARTICLE SIZE IDENTIFICATION NOTE: ALL SOILS ARE CLASSIFIED -- Boulders - 8 inch diameter or mor~ ACCORDING TO THE UNIFIED SOILS Cobbles - 3 to 8 inch diameter CLASSIFICATION SYSTEM Gravel: - Coarse - 3/4 to 3 inch - Fine - 5.0 mm to 3/4 inch Sand: - Coarse - 2.0 mm to 5.0 mm - Medium - 0.4 mm to 2.0 mm - Fine - 0.07 mm to 0.4 mm --- Silt: - 0.002 mm to 0.07 mm Clay: - up to 0.002 mm ATEC Promises · To be totally responsive to our clients' wants and needs with a constant sense of urgency. · To perform high quality services with technically superior personnel. · To perform all assignments for a reasonable fee and within budget. · To communicate with our clients frequently so there will be no surprises. · To complete our assignments and deliver reports when promised. · To review reports with our clients to be sure there are no misunderstandings. · To deliver accurate invoices to our clients within seven (7) days after the completion of the assignment or as required by the clients. · To follow up with the clients to be sure services completely satisfied their wants and needs. AI'E¢ Associates, Inc. 1~ Corporate Headquarters 8665 Bash Street Indianapolis, IN 46256-1202 (317) 577-1761 At ATEC, "Client satisfaction with a constant sense of urgency" is our goal. If you have concerns with an ATEC project or service that your local ATEC Representative has not resolved, -- please call 1-800-800-ATEC, a "hot line" to my office. We will do everything possible to satisfy your concerns. If you have received quality service, we would appreciate knowing that as well. Thank you for allowing us to work on your team. Sincerely, Gerald D. Mann President ATEC Associates, Inc. Corporate Headquarters - Client Satisfaction Hot Line 1-800-800-ATEC (1-800-800-2832)